Gas turbines typically include a compressor section, a combustion section, and a turbine section. The compressor section pressurizes air flowing into the gas turbine. The pressurized air discharged from the compressor section flows into the combustion section, which is generally characterized by a plurality of combustors disposed around an annular array about the axis of the engine. Air entering each combustor is mixed with fuel and combusted. Hot gases of combustion flow from each combustor to the turbine section of the gas turbine to drive the turbine and generate power.
During the operation of a gas turbine, anomalies may occur within the turbine's combustors that increase emissions of regulated combustion products, reduce combustor efficiency and/or reduce the part life of components within the combustor. For example, excessive flame temperatures within the combustor may cause over-firing conditions, thereby resulting in damage to the turbine's components. Additionally, excessive flame temperatures can lead to increased emissions and may necessitate increased cooling flow to the combustor, thereby reducing combustor efficiency. Similarly, lean blow-out (LBO) events, characterized by extinguished flames due to an air/fuel mixture that is too lean, increase emissions and also reduce combustor efficiency. Thus, without proper detection and mitigation of such undesirable operating conditions, a gas turbine may be not meet emissions standards, may suffer reduced longevity and/or may operate at reduced efficiencies.
Systems are known that provide for the detection of combustor operating conditions through visualization of a combustor's flame. However, such systems are typically very difficult to install within and/or remove from the combustor. As such, when a component of the system is damaged or must otherwise be replaced, a significant amount of time and money must be spent to remove and re-install the component. Additionally, many known systems require that a light portal or window be installed through a wall of the combustor casing, the combustion liner, and/or the flow sleeve of the combustor. Accordingly, a portion of such combustor wall(s) must be removed, which can result in significant leakage and wear issues.
Accordingly, a system for controlling combustor operating conditions based on flame detection that can be easily installed within a combustor without removing portions of the combustion casing, combustion liner and/or the flow sleeve would be welcomed in the technology.